The Prior Art
Terraces have been conventionally constructed using dozers, scrapers, graders, elevating loaders, and terracing machines as described and summarized in U.S. Pat. No. 3,345,764 issued to Malsam. More recently, a plow utilizing a pair of disk gangs for constructing narrow-based terraces was disclosed in U.S. Pat. No. 4,422,512 to Hodgson Jr. et al. All of the patents cited above disclose terracing machines used primarily in the construction of original terrace structures without addressing the problem of maintenance. By implication all of these terracing machines can be utilized for terrace maintenance, although, with the exception of the device disclosed in the U.S. Pat. No. 4,422,512 to Hodgson Jr. et al., the associated cost for capital investment and operation expenses for most devices renders this approach impractical for the landowner or operator. Heretofore, maintenance of existing terraces has been performed on a periodic basis by utilizing conventional disk and moldboard plows or reversible disk plows as disclosed in U.S. Pat. No. 3,045,765 to Cox et al. The major limitation associated with these conventional plows is the inability to move dirt laterally beyond the throw of a single disk or plow blade. Stacking of the dirt in a ridge with such devices is achieved solely by repeated passes in the same direction after sufficient packing of the loose dirt. Oftentimes, because of the inefficiency and soil disturbing nature of this maintenance method, the overall maintenance program of a terrace structure is abandoned.
Our invention relates to a grading device utilizing a plurality of dirt compounding disk blades arranged sequentially along the underside of an angled beam so as to grade dirt laterally from disk-to-disk. With this invention periodic terrace maintenance is easily achieved at a reduced cost of operation and capital investment. Furthermore, the disclosed invention is useful in other dirt grading applications such as original construction of narrow-based terraces, roadbed shouldering, ditching, diking, and surface excavating.